Method for manufacturing an electrochemical deposition printhead with grid control circuit and backplane
Process for manufacturing a printhead for a 3D manufacturing system that uses metal electrodeposition to construct parts. The printhead may be constructed by depositing layers on top of a backplane that contains control and power circuits. Deposited layers may include insulating layers and an anode layer that contain deposition anodes that are in contact with the electrolyte to drive electrodeposition. Insulating layers may for example be constructed of silicon nitride or silicon dioxide; the anode layer may contain an insoluble conductive material such as platinum group metals and their associated oxides, highly doped semiconducting materials, and carbon based conductors. The anode layer may be deposited using chemical vapor deposition or physical vapor deposition. Alternatively in one or more embodiments the printhead may be constructed by manufacturing a separate anode plane component, and then bonding the anode plane to the backplane.
1. A method of making an electrochemical-deposition printhead, the method comprising steps of:
forming deposition anodes by filling openings with a conductive material, the openings extending from a top surface to a bottom surface of a substrate that comprises an insulating material; and
coupling the deposition anodes to a backplane, wherein the backplane comprises:
a grid control circuit, comprising an array of row traces, an array of column traces, a row driver circuit, electrically coupled to the row traces, and a column driver circuit, electrically coupled to the column traces;
a power distribution circuit; and
deposition-control circuits, aligned with a deposition grid, wherein each of the deposition-control circuits is electrically coupled to the power distribution circuit, an associated one of the row traces, and an associated one of the column traces.
2. The method of claim 1 , further comprising depositing bonding bumps onto the bottom surface of the substrate, so that each of the bonding bumps is electrically coupled to the conductive material in one of the openings.
3. The method of claim 2 , wherein the step of coupling the deposition anodes to the backplane comprises coupling each of the bonding bumps to one of the deposition-control circuits to establish an electrical connection between each of the deposition-control circuits and a corresponding one of the deposition anodes.
4. The method of claim 3 , wherein the step coupling the deposition anodes to the backplane comprises coupling each of the bonding bumps to one of the deposition-control circuits using one or more of eutectic bonding, thermocompression bonding, or controlled-collapse solder bonding.
5. The method of claim 1 , further comprising aligning the substrate with the backplane before the step of coupling the deposition anodes to the backplane.
6. The method of claim 1 , wherein:
each of the deposition anodes comprises an insoluble conductive material,
each of the deposition-control circuits comprises one of a plurality of contact pads, and
the step of coupling the deposition anodes to the backplane establishes an electrical connection between each of the deposition anodes and one of the plurality of contact pads.
7. The method of claim 1 , wherein the step of coupling the deposition anodes to the backplane comprises bonding the substrate to the backplane using an anisotropic conductive adhesive so that an electrical connection is established between each of the deposition-control circuits and a corresponding one of the deposition anodes through the anisotropic conductive adhesive.
8. The method of claim 1 , further comprising polishing the top surface and the bottom surface of the substrate.
9. The method of claim 2 , wherein the bonding bumps are made of at least one of gold, copper, silver, lead, or tin.
10. The method of claim 6 , wherein the insoluble conductive material comprises one or more of platinum group metals and their associated oxides, highly doped semiconducting materials, or carbon nanotubes.
11. The method of claim 1 , wherein the conductive material that fills the openings is a metal-ceramic composite material.
12. The method of claim 1 , wherein the conductive material that fills the openings is one of copper, silver, nickel, tungsten.
13. The method of claim 1 , wherein the substrate is made of glass.
14. The method of claim 1 , wherein the substrate is made of silicon.
15. The method of claim 1 , wherein the substrate has a thickness from 50 nanometers to 2000 micrometers.
16. The method of claim 1 , wherein the step of forming the deposition anodes further comprises depositing anode layers onto the top surface of the substrate so that each one of the anode layers is in electrical contact with the conductive material in a corresponding one of the openings.
17. The method of claim 16 , further comprising depositing an insulation layer onto the substrate and onto only a portion of each one of the anode layers.
18. The method of claim 1 , wherein the openings are filled via an electrochemical deposition process.
19. The method of claim 1 , wherein the openings are filled via a chemical vapor deposition process.
20. The method of claim 1 , wherein the openings are filled by:
heating a powder, made of a metal material and a ceramic material, to a melting point of the ceramic material to create a matrix that holds the metal material; and
applying the matrix and the metal material onto the openings to create a hermetic seal across the openings.